Walter fitzgerald



w. PITZGERA VALVBIOP ROTARY EN I E. No. 99,423.

Patented Feb. 1,- 1870.

2 Sheets-Sheet 2.

W. FITZGERALD. VALVE 0F ROTARY ENGINE.

Patented Feb. 1, 1870 iiiuitrd giantess patent mitt-r2.

Lettenlatent No. 99,423, dated February 1, 1870.

IMPROVELIEH'I." IR VALVES 01-" ROTARY ENGINES.

The Schedule referred to in those Letters Potent and making part 01 the same To all whom it may concern:

Be it known that I, WALTER FITZGERALD, of Bos ton, ingthe county of Suffolk, and State ofiMassachm setts, have invented certain Improvements in Rotary Engines, of which the following is a full, clear, and exact description, reference being bad to the accompanying drawings, making part of this specification, in w to Figure 1 is a perspective .view of my improved romy engine.

Figure 2 is a transverse section throught-he same. 5 Fi2gure-3 isa longitudinal section, on the line a: a: of g.

. Figure 4 is a perspectiveview of the pistons, detached from the cylinder.

Figure his a perspective view of the valve.

My invention has for its object to .providea rotary engiue,'i'n,which the steam can be worked expansively, and consists'in the employment of a revolving valve of peculiar construction, in combination with a piston, provided with a slide working within a cylinder, whereby the desired end is eflected, and the steam economiredto a-greater degree than heretofore ,in this class of engines. a

To enable others skilled in 'the art to understand and use my invention, I will proceed to describethe manner in which 1 have carried it out.

In the said drawings- A represents the bed-plate, upon which rests the casing or cylinder B, which is. divided centrally by a partition, a, into two compartments, 0 D, which are closed by heads E G, secured by bolts tothe ends of the cylinder.

H is the main shaft, extending through theheads E G, and passing through the interior of the cylinder to one side of its centre.

Upon this shait, and concentric therewith,1are secured two-pistons, I- K, the diameter of each of which is less than that of the interior of the cylinder B, with which they'come in contact at a point midway between the induction and exhaust-ports, a steam-tight joint being insured by means of a spring pabking, 7, fitted into a groove in the interior of the cylinder.

Each piston I K is provided with a sliding abutment, I K, composed of a solid portion, b, which'fits-into a g'roo've, c, extendinglongitudinally through the piston,

- and is held in place by two side pieces, 0! e, which slide in grooves in the ends of the piston, eachf'side piece being provided with aslot, 8, through which the main shaft projects, by which construction the abutment is allowed to move as required.

The length of each ofthe side pieces e is such,

that as the piston revolves, the portion b, which is provided with a spring-packing, 9, will be kept con-t tinually in contact with the interior of the cylinder by the contact. of the ends of the side pieces d o with the opposite side of the cylinder, thus insuring the portionb of the abutment being in a proper position to be acted upon by the steam, as required; and by. thus constructing thesliding abutment, so that the contact of one end with the interior of the cylinder will guide and force'out the other end, I am enabled to dispense wit-hthe springs heretofore used for this purpose, which are objectionable, on account of their liability to-get out of order.

Instead of the abntments .I' K being placed in the same relative position, with respect to the induction and exhaust-ports, they are set with a variation of one hundred and eighty (180) degrees, so that the full force of'the steam will act upon one at the time when it has ceased to act upon the other. The e'nginethus becomes double-acting, producing an effect similar to that caused by'placing two cranks at diflerentangles' upon a single shaft.

h- 1', are the induction-ports, and k l the exhaustports, the former h 'i) col'nmuuicating with a circular opening, m, whichfexteuds longitudinally through an enlargement, n, on the. cylinder B.

Within this opening m, is fitted the valve L, consisting of a circular rod, provided with notches o p, through which the steam is admitted to the inductionports, when the valve L is rotated-into the proper position, by means ofagear, M, at one end, which eugages with a gear, N, on the mainshaft H The position of the notches o p is such, and the valve is so set, that steam-will be admittedthe moment. the abutment of each piston has passed its eduction-port h or i. The steam then commences to act upon the abutment, and rotate the piston, the revolution of the valve causing the induction port to be wide open when the abutmentreachcs the point 9, and entirely closed when it reaches the point 10. The steam being then entirely cut on, will work expansively, and exert a pressure upon the abutment nntil it reaches the ex haust-port; after passing which, the steam will commence to-b'e; discharged, and the operation will con tinue as before, the steam acting with full force upon the abutment of one piston, while that of the other is passing from the exhaust-port to the inductionrt. It is evident-,that instead of two pistons, each working iu'a separate compartment, as described, a singleacting engine, having one piston only, could be employed; but in such case, a heavy I or balance-wheel would, be required, to prevent any iability of the en.- gine stopping while the abutment is passingfrom the exhaust to the induction-port.-

By the employment of a rotating valve, constructed as above described, I am enabled to out ofi' the steam, bination with the c and work it expansively.

ylinder B, and one or more revolving pistons, constructed and operating substantially in Cl I the manner and fur the purpose set forth.

WALTER FITZGERALD. What I claim as my invention, and desire to 'se- Witnesses: I cure byLetters Paten13is- P. E. 'TnscnEMAcEER, The rotating valve L, with its notches o p, in c0m- W. J .CAMBRIDGE. 

